The present invention relates generally to coupling means for connecting plastic tubing to the open end of a hose. More particularly, the invention relates to conductive tube insert for coupling a plastic tubular member having a conductive inner layer to a rubber hose having a conductive inner layer such that conductive continuity is maintained between the conductive inner layer of the plastic tubular member and the conductive inner layer of the rubber hose.
Hose assemblies for transporting various fluids in vehicles, machinery, etc. are known. For installing a fuel transport tube, for example, between the metal funnel and the fuel tank in an automotive vehicle, a metal tubular member is connected to the fuel tank by means of a rubber hose which has a conductive inner surface so that there is conductive continuity in the entire fuel filler line to avoid the generation of static electricity due to the flow of fuel through the fuel filler tube. Often it is desirable or necessary to replace the metal tubular member with, e.g., a plastic tube or other tube of a different construction or to a hose such as a rubber hose. When a plastic tube is used to replace the metal tubular member, it is necessary that the inner layer of the plastic tube be made conductive to avoid the generation of static electricity. When the plastic tube is connected to the rubber hose, conductive continuity no longer exists because the conductive inner layer of the rubber hose is not in contact with the conductive inner layer of the plastic tube, but is in contact with the non-conductive outer layer of the plastic tube. Since the tubular structure transporting the fuel is required to have a high degree of fuel impermeability as well as being electrically conductive, it is difficult to provide a plastic tube which is made solely of an electrical conductive resin. Therefore, plastic fuel tubes are required to include not only an inner layer of an electrically conductive material, but also one or more other layers which provide the necessary fuel impermeability. Furthermore, it is necessary that the plastic tube have an outer protective layer made of nylon, chlorinated polyethylene, etc. Therefore, there is a need in the industry for a fuel transport tubular system which exhibits the desirable physical characteristics of a plastic tubular member and which also meets the electrical conductive continuity required for such fuel transport tubular system.